Thoroughly wash and clean beets, carrots and potatoes. You can peel all the vegetables in advance, or proceed with the vegetables unpeeled to preserve nutrients.

Prick each vegetable a few times with a fork. Place all vegetables in large pot, and enough water to cover. Bring to a boil and continue cooking for 20-30 mins, until they are easily pierced with a fork. Let vegetables cool to room temperature.

When cooked vegetables are cool enough to handle, do your best to peel them (potatoes will peel easily, beets a little less so, and carrots will likely be the hardest to peel), but don't worry if some skin remains. Chop them finely, into ½"-1" cubes, and mix them in a large bowl.

Finely chop onion, and add to bowl with cooked vegetables.

If using sauerkraut, add to bowl as is. If using pickles, chop finely and add to the rest of the vegetables. Mix well.

Stir together vegetable oil, lemon juice and salt. Season salad with dressing, mixing to ensure all vegetables coat well.

Let rest in refrigerator for 1.5 to 2 hours. Taste, and adjust seasonings if necessary.